Vertical fire tube steam boiler



Oct. 30, 1951 c. T. DENKER E'IAL VERTICAL FIRE TUBE STEAM BOILER 3 Sheets-Sheet 1 Filed Feb. 9, 1946 1951 c. T. DENKER ET AL VERTICAL FIRE TUBE STEAM BOILER 3 sheets sheet 2 Filed Feb. 9, 1946 S pm s w MMM e 4 4 4 1 g 7 E a M n 3 4 4 1 2 e r 6 4 MDR ,w T Z Z Jfi O u w P W 1 h M 2 v 2 Mw a :I- R v m v a? 2 L Z g m. w

3- Sheets-Sheet 3 w mwf i INVENTORS 174i iorn ys @ct. W, 1951 c. T. DENKER ET AL VERTICAL FIRE TUBE STEAM BOILER Filed Feb. 9, 1946 Charles Den/16a) and Job/m R. M 0 pre Patented Oct. 30, 1951 UNITED STATES PATIENTVOFFI'CE Charles T. Denker and John R.Moore, Chicago, 111., assignors to The Calefactor Corporation, Chicago, 111., a corporation of Illinois 1 Application February 9, 1946, Serial No. 646,519 3' Claims. (01. 122-122) This invention relates to steam-boilers and more particularly to the combination fire tubewater tube type of steam boiler. Fire tube-Water tube boilers are, of themselves,

relatively old in the art. However, although the fire tube-water tube boilers heretofore known to the art have compared favorably inefficiency with other types of boilers also heretofore known, the efliciency of the boilers has been undesirably low, and it is an object of our invention to construct a boiler having a greater over-all efliciency thanthe fire tube-water tube boilers heretofore known to the art.

In fire tube-water tube boilers heretofore known to theart the construction has been such that direct heat transfer relationship between the combustion chamber itself andwater introduced into the boiler was poor. In the usual form of boiler heretofore known to the art, a water header is embodied in the proximity of thejcombustion chamber and may or' may not contact the combustion chamber, and if it doescontact the combustion chamber, it does so over only a very limited'area. It is a general object of our invention to construct a boiler providing good heat transfer relationship between water introduced into the boiler and the combustion chamber thereof, and an object ancillary thereto is to associate the elements of our boiler in such a manner that water introduced into'the boiler may be in direct contactwith a substantial portion of the outer surface of the combustion chamber thereof. n

' -One: of the advantages inherent in firev tubewater tube type boilers is that heat transfer may be made to opposite sides of a relatively thin body of water within the water tubes, so that what heat is transferred is absorbed by a relatively small mass of water and the water, orthe steam formed-therefrom, is heated to a relatively high temperature. However, efficiency of a boiler depends upon, among other things, what percentage of the heat generated by the combustion of a .certain amount of fuel is utilized in heating the .water,=-the greater the percentage of the heat actually absorbed by thewater and steam the greater th efficiency of the boiler.v This has heretofore posed a diflicult problem to theart because, to obtain good combustion within the combustion chamber ofa boiler itis necessary that the flow of gases or combustion efliuent not be restricted to such an extent that insuflicient draft is realized through the combustion chamber.,j Heretofore, in fire tube-water tube boilers knpwnto the art, the construction, in general, has been such that the principal heating was accomplished 'by the flow of hot gases 'directly from the combustion chamber in parallel through the fire tubes and over the outside of the water tubes, part of the gases, flowing from the combustion chamber, passing through the fire tubes and the other part of the gases, flowing from the combustion chamberpassing over the outside of the water tubes. This construction as shown by theprior art has beenineflicient because, among other reasons,if the gases; were allowed to flow freely, so as to obtain proper draft through the combustion chambena-the velocity of the gases through and over the water tubes was so reat, and the distance that the gases traveled in heat exchange relation tojthe water or steam was so short that a proper amount of heat was not withdrawn from the hot gases and transferredto the *water or steam before the" hot gases were exhausted to the atmosphere, and, as a result,

a great amount of heat escaped up the chimney and was lost to the atmosphere; and, on the other hand, if "Dailies or other means were used to retard the flow ofgases through and over the water tubes sufficiently that the gases remained in contact with the water tubes for a sufficient length of time toeffect a transfer of the proper amount of heat from the gases tothe water or steam, the draft through'the combustion'chamberwas reduced to such an extent that proper combustion was not obtained and, therefore, a loss of efiiciency resulted. "Therefore; it will-be noted that in a fire tube-water tube boiler of the type heretofore knownto the art it has been impossible to effect both an efficient flow of hot gases, so as to provide a proper draft through the combustion chamber and also the most efllcient transfercf heat from the hot gases to the water and steam, and, therefore it was necessary to compromise between thetwo for an average efflciency. It is an object of our invention to construct 'a fire tube-water tube boiler in such a manner'that an eflicient heat transfer may be effected'from the hotgases to the water, and, also that thevelocity of-the hot gases or combustion products will be sufficient that the desirable and proper draft through the combustion chamber maybe effected. An object of our invention ancillary to this is to associate the elements of our boiler in s'u'cha manner that all the gases pass through all the heat exchange mediums thereof, in series. A further object of our invention is to assoa ciate the elements of our boiler that from the formation of hotgase's in" the combustion chamher and throughout the passage'thereof through the gases flowing from the combustion chamberflow through the fire tubes and alLgther-gases;

4 tube housing 24; and a heating flue or vertical heating chamber 'D, including a vertical water leg 25, and a vertical exhaust duct 26 interconnecting the flame box 2! and the transverse exhaust duct 24.

The lower combustion chamber l8 has side walls 21 and 28, a top wall 29, a bottom wall 30,

fantla front wallffil which' fr'nay'be 'bonstfiucted of any suitable material such as; for example,

sheet steel. The rear edge portion of the lower combustion chamber I8 is attached to the rear flowing from the combustion chamber fldwlov'er' the outside surface of the waterltubespasfdi'stirr-i V guished from part of the gases-flowing-through" the fire tubes and another part flowing 'overthe' I e ofamonduiton exhaust duct having a lower wall outside of the water tubes. 'It is a further object of our invention to as- -wall lfi of theto uter casing H], in air tight con "nection therewith, by any suitable means such s; 'for'example,- welding, and a portion of the tion chamber'l'Bl' "The flame box is in the form sociate the elements of a fire tube-water t ube boiler in such a manner-that hot gases flow over the io'uter TSllPfEJCBTlOf-ithfi cwatei'i tub'es'i transversely toztheflohgitudinal*axis thereofi;.';.' s

Anotherlvobjeet fSOfS nuns invention": is; toiiconstruct a boiler wherein there amninimuzmiof structure separatinglthe h'otgasese fromi the water arrdnsteam; gi A 1 v Yet nether iobject iof ourzinvention'f'is toi=prorvide a "oiler offsimp'lei andi economical construe tiom whichfi wills be efiicient-tin usei and will" give long servicefiw tha mirrim umiof repair arId main"- tenancei fi' 4 f 'Other and further obiects of 'the presentrirli zven tfonflwill 'b'e apparent'fromithe foll'owingvd'i script'ion" and c'laimsa and are: illustrated a in the accompanying' drawings which, .by-wayof illustrafln th'e drawingst 1 Fig-f 1 is a side elevational viewi' partly in sectIo i'e tube water tub'e bouer embodying the'principlesof our'ihventlong I Fig; 2'is; a sectioiial "view takensubstantially on tlie line 2-'-2'" r' Fig-. 1; and z I Fig? 351s" a "ectio'nal w*talien substantially The 'bo r "shown ifi the accompanying drawtl fe 'appended 'claims-z ings epnbodis an outr boilercasing or shell!!! w i topwall 1H, front wall l2, bottom"wall 'IBJsid wane H! and IS arid a-rearwall"I62 The maybe made of "any suitablematerial'such v or example, 'sl'leet 'steliandfanywalls which when the; boiler "is installed for useg are 'inclose 'proximity to walls or other structural 'members bfa'briildihg orth like; maybe insulated with a suitable ihsulation su'clias the she'etinsula non Wsmwnafnxeww the rear wall l6? frhe outer boiler 'casihg lfma'y' be" considered to em-bodyfingeneral; fourrheating areas *orrheatin}; "chambers, :A, B," C "and": D7;- the lower heating chamber A inicludingxarlower, combustionicham 'berr or firezboxs Hipand: a: lower water header i9; th rupn h at n c ambe B -i c d ner an up; per P combustiorr chamber or: pflame boxl Z0; and a steam header or steam dome 21s;- the;interme di ate heating; chamber 6.; interconnecting .;the lower heating chamben n andg-the; upper-heating ehamber,'-B;and-J comprising, water tubes:- Zi -fire QtHbBSrl3Q-fifld a; transversei-exhaustrduct v or. water 32, an upper wall 33 and side walls 34 and 35, the rea'r' edge portions of which walls are attached to the inner'surface of the rear wall E6 of the outerzca'smgst ll. ant aire tight connection any suitable zmeansksu'chzas weldingixiTheifrontsedge of the upper combustion :chamber: 20: 1s5atta'ched to the upper-"end portion of Lthe; vertical. exhaust 'suitable:..manner 'suchi-as-i'welding. The-vertical 'exhaus'tfiduct Z'B'ihas a rearcweilltiil as front wall 3 8 side walls 39: and 405 and "a bottom .zwalli-l 41'. The upper end. portion .of" the; verticalexhaust duct 26 is open to, and attached tothe upper: comr biistion chamber'ZDI The vertical exhaust-:duct'has an opening 4 la' formed in the rear wallfl'l thereof through which, as is set .forth' morei'specifically hereinafter, communication iss pro'videdtithrough the-"vertical exhaust 'duct ZE' 'i ntmthei' transverse duct 24; The trans-verse duct 24 has: alowerrwau 42 an *upper' wall flfi side wall's l l and '45 a'nd3a front} wall -46 The rear iedge' portion er the tIaIlSVBI'S" duct 2 4f attachedto the -inrierfisu'r"- face of the rear wall l fij of'the outer shell I 0 in an airtight connection by any suitable" means suchasi for example, :we'ldin'gf. :Tl'le 'fron-t wall 46- of; thetransverse duct 24Fhas an op'enin g formed therein which 'is tcomplementary to 5 the opening llafo'rmed in the vertical duct 26, and peripheral edge portions;of fthe openings in the vertical duct' ZS and the-transverseduct 24;re-

spectively; are connected by a-collar -4l which maybe welded thereto. The plates lfi and 3T are also connectedat spaced points by tubular-stay bolt'slfiaj as-shown'in'Figs; fanc e -so as'to'pre ventbulging thereof. These tubular stay bolts may be brazed to the plates 46 and 3]. 1

The'top wall33 andflside wallstd' and 35" of the flameb ox 2 0, the-front-wall 38 and the sid wa1ls"39and 400 f the vertical =duct'26', theside Walls M and 45 of the-transverse duct =24; the sidewalls 2'! and 28, the bottom wall?!) and the front 'wall'3i of the'lower combustion chamber I8 'areg-each attached to 'the respective adjacent walls of the outer casing; Ill b'y'means ofsuspension bolts 48 and are supportedtherebyin spaced relation to. the outerishell' l0. r The lower firebox IBis interconnected 'to'ythle flame b ox20 by meansfof'the firetubesiill The loweriend of the fire tubes 23 are ins'ertedthrough the im er Wa11i29 J'OfjjhfilOWCljfiIt-l box ,IB and thereto by any 'suit Suitable fuel such; as,;f 'jexample, commerfci'al; water. as, natural jg or thelike maybe mixed with. ai r, and f. (12133; suitable means, such: as, for .exampljc burner'sg'l 28,V Eigjs...1;and i,2, connected; toeconventionaL feeding apparatusjhljy QQ tE a m l-r str ame a? gar-3561 barriers I28 and 'the'feedifig'apparatus "I29 are shown in'tlie' drawings to illustrate a preferred embodiment of our-invention and not byway'of limitationthereto', and that other typesof burners'andffedif gapparatus maybe used without departing from the purview of our invention.

f'Th'e hot gases "and othefcombustion effluent resulting from combustion of fuel' within the lower combustion chamber 18 new upwardly through'the fire tubes '23 into the-fiamebox'fll from which "they flow "downwardly. through the 1- vertical exhaust duct 26, 'substantiallyi'horizo'n 1 tally 'th'rough the transverseduct fl from? which? they"pa'ss' through an opening' 49, provided-in" therearwall thereof "into a fiue or'chimney 50-" and are exhausted to the atmospheref'f Thus-it will' b'enote'd that the flame box 2 fli'the vertical exhaust duct'26andthe' transverse exhaust duct "arih "of'themselves, form an efficient heatex- -t chaiige' element having good hea't exchange rela-t-t tionship with water or steam in th'e 'boileniand,"

together form an exhaust duct through which hot gases or combustion products can efficiently "flow from the combustion'xchamberand fire tubes to the chimney 50 mosphere.

Itwiu-he noted that; although" we refer-to use liquid or gaseous'fuelsfour invention is not" limited to the use thereof, and solid fuels may" normally rises into the water leg surrounding 'and' be exhausted 'to. the at-*' :bolts-46w into thetransverse duct 24 in which thetransverse duct 24*and the vertical duct 25 on-all sides except the rear side of the transverse duct 24. by and extend vertically through the transverse duct 24; with the upper and lowerend-portions ofthefwater tubes 22 extendingythroug-h the top and bottom walls 43 and 42 respectively, of the transverse duct 24 and being-attached-thereto in- -a sealed connection by any suitable means such as, for example, by welding. Each of the.

water'tubes 22 arepositioned to encircle a fire tube 23, the inner-wall of the water tubes 22 being spaced outwardly from the outer wall of the fire tubes23, as best'shown in Fig. 3. It will be noted that when water isintroduced through the inlet 5| into thetwaterheader l9 and rises intothe water leg 2 5, that water also rises into the"'-wa-tert'ubes 22 surrounding the fire tubes 23. combustion taking place within the lower firebox |8 .and the outer shell thereofi'heated-tby the combustion} the waterlentering the boiler is initially heated in the water headerl l9 while it is fiowing from the inlet 5| 'into the water-tubes 22 fandt the water leg .25 and that the thin layer of 'water' within the water tubes 22 is further heated from the inside by any continuation of the combustion which takes place within the fire tubes 23 and by the passage of hot gases verti cally through the fire tubes 23.1into the-upper fire chamber 20.

If suitable provisions were not made, water flowin into the water header 9 would, choosing the path of least resistance, tend to rise into the water leg 25 rather than into the relatively restricted areas between the water tubes 22 and the fire tubes 23. To prevent this and toassure The water tubes are carried Thu it willr-be 'noted thatqwith properieeding'fof water into the water tubes, we

provide'apanel which extends outwardly from the bottom wall 4| of the transverse duct 24 and the 'verticali duct 26,5respectively, and underlies the waterllegs 25.-"The panel 60 has openings 6|"formed therein which are of sufiicient size that'the "rise of water into'the water legs 25 is-"partially restricted so that water tends to rise equally from the water header 9 into the water tubest'22- and the water leg 25.

,Th'ei'e'xhaust gases which enter the fiamebox' 20 "fromtheupper end, portion of the fire tubes 23"pass" downwardlythrough the vertical -exhaus't-du'ct 26, which is heated thereby, and additional heat is therebyv supplied to the water which surrounds the vertical duct 26, such as, for-example, the water in the'water leg 25. From the, vertical exhaust duct 26' the exhaust gases pass through the opening- 4-laaand the tubular stay theyi'passsubstantially horizontally across the outside'of the water, tubes 22, thereby heating the water and steam within the water tubes 22 from theoutside thereof, and pass out through the opening into the flue or chimney 50 from which they escape into the atmosphere. I

Visual echecks may beconstantly made on the temperature'of'the steam and-the level'of the; water "within our boiler by referring to the ther:

mometer-and the water levelgage attached to connections 53 and 54, respectively, shown in:

:From the foregoingit will be noted that the 7 water within the water tubes 23 is heated bothfrom within and without by hot gases passing through the fire tubes '22'and the exhaust duct 24- respectively." Also it will be noted that the water; vapor or steam which passes upwardly from :the water-tubes-22 or the water leg 25- w- -into -thesteam header 2| is further heated by the combustion efiiuent and hot gases which pass through'the upper combustion chamber 20. From the steam-chamber 2|, the steam passes from the boiler ill-through theoutlet 52 from whence it circulates into the heating system or other system in which-nit is used.

Eurthermoreit will be apparent, from the foregoing, that the flow of gases from the lower combustion chamber l8 through the fire tubes 23, the-upper fire box 2ll,=the vertical exhaust duct-t26, -the transverse exhaust duct 24,. and

the'chimney or flue 50 to the atmosphere is relatively unrestricted but is so designed that efficientheat transfer is. effected between the combustionproducts and the water and steam from the initial combustion within the lower fire box |8 and throughout the passage of the combustion products throu h the boiler from the lower firebox l8 until the gases enter the chimney. or fiue 50.. Furthermore, it will be noted that the water whic'hmenters from the inlet 5| is initially heated within the water head-. er--|-9 so; that the water which enters the water tubes-22 has been-pre-heated and that there- ,fore the heat on both sides of the relatively thin --layer of water tubes 22 furnished by the gases-massingthrough the fire tubes 23 and through thetransverseduct 24 is fully capable lationshipf between: the gas and: the? .watenor:

steami is. prolonged and change. is effected. .r

-A;lso,-'"it: will be notect that ouri; invention providesi'an efficient.- :boiler wherein, although the exhaust gases are relatively unrestricted; intheir new .to the atmosphere so that a good draft through the combustion.chamber-thereof effected; the passage ofthese gases so'c'laid.

out and the elements ofouraboiler" are associated Witheach other in sucha manner that'efficient a: maximum: heat: ex-

heati transfer: is realized from the combustion:

produc'ts'to'thewaterand steam to be heated? so thatTa'min-i'mum' of heat escapes throughithe 'flueflrtobe-lost to the atmosphere.

Furthermore, it will-be noted that byvarying.

the size of our boiler unit, without changing the principles or operation thereoflro'ur boiler unit may "be equally well adapted :either foicommercial: or residential heating purposes.

Ailsciit will be noted that the present-invention accomplishes its intended objects some or: which have been specifically referred to hereinbefore and other of which will be apparent from the foregoing description taken"in" conj'unction with the accompanying drawings a 7 Hence, while we have'illustr'ate'd and 'describcd the preferredembodiments of" our invention-gitis to be understood that these are capable of variation and modification and We therefore do not wish to be limited to the precise details set forth, but desire to avail ourselves of such changes and alterations as fall within following claims.

' -We claim:

I. A boiler comprising an outer casing, a, lower combustion chamber mounted within said casing the purview of' the V and having outside'wall's spaced inwardly from walls of said casing, a flame box mounted within said casing above said combustion chamber and combustion chamber and flame box, an exhaust duct mounted within said casing between said combustion chamber and flame box and having outside walls spaced from Walls of said outer casing, means for transferring exhaust gases having outside walls spaced inwardly'irom walls of said casing, fire 'tubes interconnecting saidf from said flame box to said exhaust duct, water tubes mounted within said casing around said fire tubes and extending through said exhaust duct,' and means for introducing water into said outer casing in directcontact with said lower corrlbustionchambenand means for exhaustingsteam from the upper-end portion of said casing.

.2; A boiler comprising an outer casing having our;

top, bottom, front, rear and side walls, a'lower 3 combustion chamber mounted within said cas' ing. and supported thereby, an upper chamber. mounted within said casing and supported thereby, vertically extending fire tubes interconnecting said upper and lower chambers, a substantially horizontally extending exhaust duct mounted in said outer casing and supported thereby in position between said upper and lower chambers, said lower chamber, said upper chamber and said horizontal exhaust duct each having top, bottom, front and side walls and having the rear edges of said top, bottom, and side walls attachedto theinner surface of said outer casingain air tight connection therewith, aflueinterconnecting said horizontally extending exhaust; duct and. said upper combustion chamber;"

.watervtubes surrounding. said 'fire tubes and extending through said horizontally extending exhaust duct-said chambers and said exhaust duct being disposed relative 'to each other and: toisaidt casing so asz-to' afford water-receivingx-j spaces inisaid 'casingbetween predetermined por-- tion's era-said chambers-rand saidexhaust :duct

and between said casing and; predetermined-p0r+-= tiODSfDfi'Saiu chambersand' :said. exhaust duct: and which spaces are so disposedthat when. said .spa'cesare'full-ofwaterisaid water is indirect.)-

contact With the top; bottom, front andflside'wallsrof said combustion chamber, the i bottom; front: and='side-wallsz of said horizontally extending": exhaustvdu'ctyia'nd the outer. surfaces of'saidi fire"? said outer casing. 1r

.atubes within said water tubes, andvme'ans-for'= feeding-wateri-into said' water-receivingspaces inf 3:"A boilercomprising acasing, a lower fire box mountedzinz= said casing; and partially spaced therefrom, anwupperiflame boxmounted in. said casing and partially spaced therefrom, fire'tubes connecting saidt fire 'box with said flamefbox, a

water header:comprisingcthe space between said fire boxand 's'ai'd casing and substantially sur-'-'? rounding the op, bottom and side portions of said 'fir' box, a; steam "header comprising" the spacebetween said fiame box and said casing and substantially surroundingthe top, bottom and 'side p'ortions 'ofsaid 'flame box, means for-"= introdl'icing'water "iiitosa id watefheadei intointimate 'heat ex hange relationship with saidfire'box, Water tubes surrounding said fire tubesand connecting saidwa'ter header with said steam headerfa panel-mounted inf'the lower end por tions of said water tubes within said casing, said pahel-having openings therein for the passage' ofwater;' between sa'id he'aders exteriorally .otsaid'f water tubes' and means including ah f exhaust duct for exhausting hot; gases from said flame dfii box'tofthe atmosphere, said last named means being adapted-Ito guide the hot gases over the. outsicssurrsce 'or said water tubes in intimate heat exchange relationship therewith.

' CHARLES T. DENKER". Joni; R. MOORE.

I REFERENCES CITED The.{following references. are of record in the filepf this patent:

' Sawyer, Nov. 6. 1945;- 

